How can I draw an image with alpha on a transparent canvas on Xorg?

I'm using Linux and I would like to create a transparent window and load in it an image with an alpha channel, so that the windows below show through the alpha channel. What's the simpl开发者_运维知识库est way of doing this? I'd use Python if possible, but I'm not fussy.

You can't directly do it with X11. It does not know what transparency is.

In order to draw a translucent window, your window manager (which must be a COMPOSITE window manager) has to provide this function. So try studying your WM specs and see if and how it handles transparency.